1. Field of the Invention
The present invention relates to an electron emission display and, more particularly, to an electron emission display capable of improving luminous efficiency by not forming a transparent conductive layer under an effective region including a fluorescent layer.
2. Discussion of Related Art
In general, an electron emission device uses a hot cathode or a cold cathode as an electron source. An electron emission device using the cold cathode may employ a field emitter array (FEA) type device, a surface conduction emitter (SCE) type device, a metal-insulator-metal (MIM) type device, a metal-insulator-semiconductor (MIS) type device or a ballistic electron surface emitting (BSE) type device.
Using these electron emission devices, an electron emission display that further includes various types of backlights, an electron beam apparatus for lithography and other components can be implemented. The electron emission display includes an electron emission part on a first substrate and an image forming part on a second substrate opposite the electron emission part.
The electron emission part includes a bottom substrate, an electron emission device formed on the bottom substrate, a cathode electrode and a gate electrode configured in a matrix shape on the bottom substrate. The electron emission device emits electrons.
The image forming part includes a top substrate, a fluorescent material formed on the top substrate and an anode electrode electrically connected to the fluorescent material. The electrons emitted from the electron emission part collide with the fluorescent material to generate light.
In addition, the image forming part further includes a light-shielding layer for absorbing or shielding external light and preventing optical crosstalk. An example of a method of fabricating the light-shielding layer is disclosed in Korean Laid-open Publication No. 1999-2071.
A conventional method of fabricating a light-shielding layer will be described in conjunction with the accompanying drawings. FIGS. 1A to 1D are cross-sectional views illustrating a manufacturing process for an image forming part having a light-shielding layer formed thereon according to the prior art. Referring to FIGS. 1A to 1D, a method of fabricating the light-shielding layer, according to the prior art, includes forming an anode electrode 120 on a top substrate 110 and forming a light-shielding layer 150 on the anode electrode 120.
First, referring to FIG. 1A, the anode electrode 120 is formed on the top substrate 110. The anode electrode 120 may be referred to as an ITO electrode since it is made of indium tin oxide (ITO). Next, referring to FIG. 1B, fluorescent layers 130 are formed on the anode electrode 120. The fluorescent layers 130 are formed separately from each other using a slurry method. While the fluorescent layer is formed by the slurry method, the fluorescent layer is formed using a screen printing method, an electrophoresis method, or a transfer method.
Next, a metal material, for example, Cr, is deposited and line-patterned between the separately formed fluorescent layers 130, see FIG. 1C. Then, the Cr 140 formed between the fluorescent layers 130 and the anode electrode 120 made of ITO causes an oxidation reaction to form black CrOx. The oxidized black CrOx becomes a light-shielding layer 150 for absorbing or shielding external light, see FIG. 1D. As described above, the light-shielding layer 150 may be made by the reaction of ITO and Cr or a pattern printing method using black Fodel or Ag Fodel. A power supply layer (not shown) for applying a voltage to the anode electrode 120 from an external power source is formed to be electrically connected to the light-shielding layer 150. The power supply layer is made of an ITO electrode and Cr.
The fluorescent layer 130 is formed on the ITO electrode 120 that is applied to the top substrate 110. As a result, because the light generated by the collision of the electrons emitted from the electron emission device and the fluorescent layer is emitted to the exterior through the ITO electrode, the brightness of the generated light may be lowered in proportion to the thickness of the ITO electrode. In addition, because the power supply layer is made of the ITO electrode and Cr, the Cr layer is likely to corrode due to high voltage applied from the exterior.